Spring-scale.



N0 MODEL.

PATENTED AUG. 2, 1904. S. R. MUNSON.

SPRING SCALE.

APPLICATION FILED FEB. 9, 1904.

2 SHEETS-SHEET l.

Ill

In Var; 22 6 pinion 7 of the indicator-shaft 8.

' To all whom it may concern:

UNITED STATES Patented August 2, 1904.

PATENT OEEIcE.

SAMUEL R. MUNSON, OF NEIV BRITAIN, CONNECTICUT, ASSIGNOR TO LANDERS, FRARY AN l) CLARK, OF NEW BRITAIN, CONNECTICUT, A

CORPORATION.

SPRING-SCALE.

SPECIFICATION forming part of Letters Patent No. 766,460, dated August 2, 1904.

Application filed February 9, 1904. Serial No. 192,774. (No model.)

Be it known that I, SAMUEL R. MUNsoN, a citizen of the United States, residing at New Britain, in the county of Hartford and State of Connecticut, have invented a certain new and useful Improvement in Spring-Scales, of which the following is a specification.

My invention relates to improvements in weighing-scales; and the main object of my improvement is to provide an adjustment of the counterbalancing-spring to different temperatures, in connection with which I also provide a tare adjustment.

In the accompanying drawings, Figure 1 is a sideelevation of my improvement with so much of an ordinary form of spring-scale as is necessary to show its connection therewith, a small portion of the scale being shown in vertical section. Fig. 2 is an enlarged sectional elevation of the principal parts of the same, the plane of section being on a line extending through the axis of both counterbalancing-springs. Fig. 3 is a sectional plan of a portion of the frame and counterbalancingspring supports, the plane of. section being indicated by the line a: m of Fig. 2.

A designates the frame of the scales, from the upper part of which two counterbalancingsprings 4 4 are suspended, the lower ends of the said springs being connected to the drawbar 5 in any ordinary manner, the said drawbar having mounted thereon in any ordinary manner the rack-bar 6, that engages with the By the sides of the springs the air-cylinders 9 are mounted, and the piston-rods 10 of the pistons for said cylinders are also connected to the draft-bar, all so far as specifically described being of an ordinary construction and for which any ordinary spring-scale may be substituted.

The suspending device 11 for this scale is attached to the upper end of a stud or shaft 12, that is made rigid with the frame A and projects at the upper end thereof. This stud may be rigidly secured to the frame in any ordinary manner; but, as shown, its lower end 13 is screw-threaded and is screwed into a hole in the boss 30 of the frame until it strikes bottom.

The upwardly-projecting portion of the stud is cylindrical, and on it there is mounted a gearwheel 14, having an upwardly-projecting hub 15, the periphery of which at the upper end may be knurled, as at 16, Fig. 1, to facilitate turning the hub and wheel. A second gearwheel 17, having a shorter tubular hub 18, which is also knurled, is mounted on the hub 15 of the first wheel 14. These wheels 14 and 17 form intermediate wheels between other wheels hereinafter described.

The springs 4 are suspended from the frame by the screw-threaded rods 19, the lower ends of which rods are provided with a flange or spring-engaging web 20 for entering between the coils of the ordinary spirally wound springs 4, whereby the entire weight thrown on the said springs is transmitted to the said rods. These rods pass through unthreaded holes 21 in the upper cross-piece 22 of the frame A, and upon the threaded portion of the said rods which projects above this crosspiece a centrally-threaded gear-wheel 23 is placed that engages the teeth of the gearwheel 14. This centrally-tlneadedgear-wheel acts as a nut to prevent the rods 19 from being pulled downwardly through the unthreaded holes in the cross-piece 22 and for the purpose of the temperature adjustment acts the same as if the threaded hole was in the cross-piece. At the upper ends of the said screw-threaded rods 19 a gear-wheel 24 is rigidly mounted, so as to rotate with the said rods. It may be thus fixed on the said rods in any ordinary manner; but, as shown, the gear-wheel 24 is centrally threaded and a stop-nut 25 is placed on the rods above and below the said gear-- Wheel to firmly lock it against rotating on the rod and necessitating the rotation of the said rod with the said wheel. The intermediate gear-wheel17 is made thick vertically, so that it may properly engage the wheels 24 when they rise and fall, as hereinafter described. The extreme upper ends of the springs 4 are arranged on a winged hub 26, having holes 27 at the junction of the hub and wing and webs 28 on the side of the hubs that is opposite the said holes. In Fig. 2 I have shown the right-hand Wingedhub in section, together with a portion of the spring 4, while on the left-hand side I have omitted the spring and shown the winged hub in front elevation. In this connection it may be noted that the parts are alike on both sides of the scale and that when the intermediate wheels 14 17 are removed either side may be separately adjusted as to the effective length of the springs. The upper coils of the spring pass through the holes 27 and over the webs 28 to the upper ends of the winged hub, and thus connect the said springs thereto in a well-known manner of connecting said springs to analogous parts. The pull on the springs, however, comes entirely on the screw-rods 19 through the flanges or spring-engaging webs 20. The two winged hubs and upper ends of the two springs are connected together by means of the yoke 29, whereby the said winged hubs will by the friction of the springs thereon hold the said springs against rotating on their own axes.

It has been demonstrated in practice that spring-scales when adjusted to the zero-mark in one temperature will vary from the correct weight when used in a materially-difi'erent temperature. The lower the temperature is the less will be the weight indicated. This can be regulated by adjusting the effective length of the springs. The springs are made stiffer by decreasing their effective length, and vice versa. By holding the wheel 14 and its hub against rotation and turning the wheel 17 the screw-rods 19 are screwed up or down in the wheels 23, which act as nuts or threaded holes. When these screw-rods rotate, the springs. 4: are held against rotation by the winged hubs and yoke, while the spring-engaging webs 20, rigid on the said rods, rotate between the coils of the springs and, in effect, screw the said rods up or down therein, so as to leave a greater or less length of spring between the said rods and the connection with the draw-bar at the lower ends of the said springs, whereby the springs are shortened or lengthened, according to which way the webs 20 are screwed. The friction between the springs and winged hubs should be in excess of the friction between the webs 20 and adjacent coils of the spring, so that the said springs will not rotate with the said webs. In order to adjust the spring for tare, the wheel 17 and its hub 18 are held against rotation and the hub and wheel 15 and 14 rotated, thereby screwing the screw-rods 19 up or down within the gear-wheels 23, which act as threaded holes, so as to raise the springs and parts connected therewith bodily up or down without changing the length of the said springs. By this raising or lowering the springs to bring the indicator to the Zeromark when a pan or other tare is pulling down on the draft-bar anything placed in said pan or on the said tare will have its weight 001'- rectly indicated, as in ordinary scales with tare adjustment.

It is apparent that some changes from the specific construction herein disclosed may be made, and therefore I do not wish to be understood as limiting myself to the precise form of construction shown and described, but desire the liberty to make such changes in working my invention as may fairly come within the spirit and scope of the same.

I claim as my invention 1. In a spring-scale, the combination of a spring with means for holding the said spring against rotation, a screw-rod extending axially into the said spring, a spring-engaging web mounted on the said rod within the said spring, means for supporting the said rod and connected spring, and means for screwing the said rod longitudinally of the spring to change the effective length of the latter.

2. In a spring-scale, the combination of the frame with two springs, screw-rods extending axially into the said springs, spring-engaging webs mounted on the said rods within the said springs, means for holding the said springs against rotation, and means for rotating the said screw-rods together within the said springs to change alike the elfective length of both springs.

, 3. In a spring-scale, the combination of the frame with the screw-rods mounted on the said frame, spring-engaging webs mounted on the said rods, the springs with their upper portions surrounding a portion of the said screw-rods and in engagement with the said spring-engaging webs, means for confining the said springs against rotation, gear-wheels mounted on the said screw-rods to rotate therewith, and an intermediate gear-wheel connecting and driving the said two gearwheels.

4. In a spring-scale, the combination of the frame with the screw-rods depending from the upper portion of the said frame, springengaging webs mounted on the said screwrods, springs with their upper portions surrounding a portion of the said screw-rods and in engagement with the said spring-engaging webs, means for confining the said springs against rotation, centrally threaded gearwheels on the threaded portion of the said screw-rods, and arranged to be supported on the said frame, gear-wheels mounted on the said rods to rotate therewith, and separatelyrotating intermediate gear -wheels between the two pairs of gear-wheels on the said rods, whereby when one of the said intermediate gear-Wheels is rotated and the other is stationary the screw-rods are rotated to change the effective length of the springs, and when the other of the said intermediate gear-wheels is rotated and the first one stationary the springs and screw-rods are raised or lowered bodily without rotating the said screw-rods or changing the effective length of the springs.

55. In a spring-scale, the combination of the frame, with the screw-rods mounted on the ISO upper portion of the said frame, spring-engaging Webs mounted on the said rods, the springs with their upper portion surrounding a portion of the said screw-rods, means for connecting together the upper ends of the said springs andalso holding the said springs against rotation, and means for rotating the said screw rods together Within the said springs to change in like manner and extend the effective length of both springs.

SAMUEL R. MUNSON. Witnesses:

GEORGE A. STOOKMAN, G. W. KENT. 

